#include<iostream>
#include<algorithm>
#include<vector>
#include<fstream>using namespace std;typedef vector<double> feature;
typedef int label;class PercepMachine
{private:vector<feature> dataset;vector<label> labelset;double learningrate;double vector_multi (const feature &x, const feature &y){double sum = 0.0;for (int i = 0; i != x.size(); ++i){sum += x[i] * y[i];}return sum;}feature vector_multi(double x, const feature &y){feature temp;for (int i = 0; i != y.size(); ++i){temp.push_back(x*y[i]);}return temp;}feature vector_add(const feature &x, const feature &y){feature temp(0);for (int i = 0; i != x.size(); ++i){temp.push_back(x[i] + y[i]);}return temp;}
public:feature w;double b;PercepMachine(vector<feature> &traindata, vector<label> &trainlabel, feature &startw, double startb, double rate) :dataset(traindata), labelset(trainlabel), w(startw), b(startb), learningrate(rate){}void calculate_percep();
};void PercepMachine::calculate_percep()
{vector<int> flag(dataset.size(), 1);while (find(flag.begin(), flag.end(), 1) != flag.end()){for (int i = 0; i != dataset.size(); ++i){double multi = vector_multi(dataset[i], w);if ((multi + b)*labelset[i] <= 0)//有误分类点{flag[i] = 1;w = vector_add(w, vector_multi(learningrate*labelset[i], dataset[i]));b = b + learningrate*labelset[i];}else{flag[i] = 0;}}}
}int main()
{ifstream  fin("data.txt");if (!fin){cout << "can not open the file data.txt" << endl;exit(1);}/* input the dataSet 假设是平面数据，存储在txt文件中3列多行，最后一列存储类别信息1或-1*/int feature_dimension = 2;vector<feature> traindata;vector<label> trainlabel;while (!fin.eof()){feature temp_data;double temp;for (int i = 0; i < feature_dimension; ++i){fin >> temp;temp_data.push_back(temp);}traindata.push_back(temp_data);label mylabel;fin >> mylabel;trainlabel.push_back(mylabel);}feature startw(2,1);double startb = 1.0;double rate = 0.5;PercepMachine permachine(traindata, trainlabel, startw, startb, rate);permachine.calculate_percep();cout << "w=" << "("<<permachine.w[0] << " " << permachine.w[1]<<")" << endl;cout << "b=" << permachine.b << endl;return 0;}